A ligament is a piece of fibrous tissue which connects one bone to another within the body. Ligaments are frequently damaged (e.g., detached, torn or ruptured) as the result of injury or accident. A damaged ligament can impede proper stability and motion of a joint and cause significant pain. A damaged ligament can be replaced or repaired using various procedures, a choice of which can depend on a particular ligament to be restored and on the extent of the damage. When ligaments are damaged, surgical reconstruction can be necessary, as the ligaments may not regenerate on their own.
An example of a ligament that is frequently damaged as a result of injury, overexertion, aging and/or accident is the anterior cruciate ligament (ACL) that extends between a top of the tibia and a bottom of the femur. Another ligament that is often damaged and may need to be replaced is a posterior cruciate ligament (PCL). A damaged ACL or PCL can cause instability of the knee joint, arthritis, and substantial pain.
ACL repair typically includes the use of a ligament graft replacement procedure which usually involves drilling a bone tunnel through the tibia and up into the femur. Then a ligament graft, which may be an artificial ligament or harvested graft, such as a tendon, is passed through a tibial portion of the tunnel (sometimes referred to as “the tibial tunnel”) across the interior of the joint, and up into a femoral portion of a tunnel (sometimes referred to as “the femoral tunnel”). One end of the ligament graft can then be secured in the femoral tunnel and another end of the graft is secured in the tibial tunnel, at the sites where the natural ligament attaches.
A common ligament reconstruction procedure involves using an autograft, which is a portion of the patient's own tendon that would replace the damaged natural ligament. The autograft is often a hamstring tendon, though other tendons can be used (e.g., a patellar tendon). The ligament graft can also be obtained from a donor (“allograft”).
Ligament augmentation and replacement procedures typically require preparation of a harvested ligament graft using various techniques to secure the graft for passing through the drilled tunnels and to strengthen the graft prior to fixation. The preparation may involve cleaning and measuring the graft, and then affixing sutures to free ends thereof. The thus prepared graft can be tensioned prior to being inserted into the femoral and tibial tunnels.
Various techniques for graft preparation exit, which have advantages and certain drawbacks. For example, sutures may be applied in such a manner that they cut through the tendon thus causing trauma to the graft. One cause of this phenomenon is that the tension may not be distributed uniformly along the length of the stitching. This, as well as other issues with graft preparation techniques, can cause the graft to deform and to be subjected to undesirable excessive elongation when a load is applied thereto. Furthermore, many of the conventional approaches are complicated and may therefore take up a significant portion of time of a surgery.
Accordingly, there is a need for improved graft constructs and techniques for preparing such graft constructs.